Your Kidneys

Transcript

Maj West
Your kidneys filter your blood to remove waste. Let’s hear what Dr. Phillips has to tell us about the kidneys.

Dr. Phillips
Your kidneys are two bean-shaped organs located just below your ribcage. Before blood in the circulatory system returns to your heart, it must go through your kidneys to filter out waste. Each kidney contains about a million tiny filtering units called nephrons. The nephron has a two-step process for filtering your blood. This process starts in a part of the nephron called the glomerulus. The glomerulus allows fluid and waste products to pass through, but not blood cells and larger molecules, such as proteins. The filtered fluid then goes through a part of the nephron called the tubule. There, nutrients and minerals needed by the body are sent back into the bloodstream, and waste is sent on as urine to the bladder. Healthy kidneys filter 120 to 150 quarts of blood and produce one to two quarts of urine every day.

Your kidneys also play an important role in regulating blood pressure. When you have low blood volume or a decreased salt level, your kidneys release an enzyme called renin. Renin activates certain hormones that cause your blood vessels to constrict. At the same time, a hormone produced by your adrenal glands, called aldosterone, tells your body to retain more water and salt. The constricted blood vessels and the increase in salt cause your blood pressure to rise.

When blood arrives at the kidney at too high a pressure, it can cause damage to the kidneys and affect the kidneys’ ability to filter out waste from the blood. This can lead to chronic kidney disease, which can increase blood pressure even further.